My supply is similar to Nelson's F6 supply (or maybe F7, I can't remember which), which added separation of channels after the resistors. The factory J2s I think used the previous supplies, so they'll also work fine.
There is no thermal cut-out built in to my designs. I think some of Nelson's later production designs have a thermal cut-out in the PSU.
Amp is silent with no input. I don't recall a turn-on thump (the thermistor in the PSU likely provides enough of a soft start).
There is no thermal cut-out built in to my designs. I think some of Nelson's later production designs have a thermal cut-out in the PSU.
Amp is silent with no input. I don't recall a turn-on thump (the thermistor in the PSU likely provides enough of a soft start).
@meanie, that is a wonderful build coming along. Thanks for the link to the enclosure.
@JeffYoung
- Ohmite says tnp-10 series has been discontinued (TNP10 Series | Ohmite Mfg Co) . Can you suggest an equivalent? Mouser India is out of stock on the 200 Ohm and 330 Ohm and they don't have makes from other manufacturers.
- Is it possible to lower the power output to say 15Watts instead of 25Watts per channel without changing the design? Just a question because for high sensitivity speakers lesser watts are fine. The F3 is an option but just checking if something is possible with the J2.
@JeffYoung
- Ohmite says tnp-10 series has been discontinued (TNP10 Series | Ohmite Mfg Co) . Can you suggest an equivalent? Mouser India is out of stock on the 200 Ohm and 330 Ohm and they don't have makes from other manufacturers.
- Is it possible to lower the power output to say 15Watts instead of 25Watts per channel without changing the design? Just a question because for high sensitivity speakers lesser watts are fine. The F3 is an option but just checking if something is possible with the J2.
lowering the rail voltage will lower the output voltage.......a 40% decrease will give you less power by about half...
Search back in the thread. Someone substituted a TO220 package resistor that I think had better pricing than the Ohmites as well. A Caddocks maybe? I can't remember....
That enclosure looks like a good price if you live in the East, but if you live in the US the shipping is $90! And that’s for a chassis without heatsinks! !
Shipping from EU to US just as expensive.
Only cheap if you have one container to fill.
Patrick
Only cheap if you have one container to fill.
Patrick
So I can safely lower the rail voltage till I get sufficient loudness with premap volume range (say between 9'0 clock - 3'0 clock) on the preamp?
Yes, Caddock seems to have a replacement.
Shipping to India next door is also expensive 🙂 Actually we pay significant shipping charges when importing (from anywhere) even for small packages like electronic components + 45-48% customs duty.
Yes, Caddock seems to have a replacement.
Shipping to India next door is also expensive 🙂 Actually we pay significant shipping charges when importing (from anywhere) even for small packages like electronic components + 45-48% customs duty.
No one seems to have SJ170 GR (even punkydawgs). diyAudio is out of A grade LSK170.
Any suggestions on where else to look?
Any suggestions on where else to look?
Thanks Jeff.
Regarding the SJEP120R100 I thought there was no need to match them until I saw a GB initiated by EUVL (Patrick) for curve tracer matched pairs. My question is does it matter for the J2 and if so what are the matching parameters while purchasing them?
Regarding the SJEP120R100 I thought there was no need to match them until I saw a GB initiated by EUVL (Patrick) for curve tracer matched pairs. My question is does it matter for the J2 and if so what are the matching parameters while purchasing them?
There's no value in matching between the CCS and the output device, and unless you're in a studio (or a completely symmetrical room with symmetrical furnishings) I can't imagine matching between channels will make much difference either.
If you have matched pairs/quads you might as well use them, but if you don't it wouldn't worry me.
I bought one of Patrick's matched quads but kept them for some as yet unknown project and used less-well-matched pairs from TeaBags' GB (from back when they were still in production) for my J2.
If you have matched pairs/quads you might as well use them, but if you don't it wouldn't worry me.
I bought one of Patrick's matched quads but kept them for some as yet unknown project and used less-well-matched pairs from TeaBags' GB (from back when they were still in production) for my J2.
One additional disclaimer: I'm an amateur. Readers must be willing to accept that any of my advice could be wrong. 😎
Is there a desired range for the parameters or is it just required that they be close to each other?